My great grandmother is buried in the military section of a large cemetery. All the headstones in that one are flat and the same size. The rest of the cemetery has flat stones, but they are not regulated in size. One of her husbands (not my great grandfather) was a vet, so they allowed her in. I remember someone in the family saying that her age (108) was a factor for letting her be buried there, but I could not figure out why.

Isn't it interesting that most military cemeteries have those flat stones, but the national cemeteries that are maintained by the military have the upright lined up crosses?